[sheepdog] [PATCH v2 02/10] trace: create a caller list in tracer_init()

MORITA Kazutaka morita.kazutaka at gmail.com
Fri Aug 9 05:21:56 CEST 2013


From: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>

In tracer_enable(), we replace all the mcount() calls in the caller
list with trace_caller().  However, we create the caller list
dynamically; we update the list when sheep calls a new function which
is not in the list for the first time.  This means that we cannot
trace the functions which were not called before we call
tracer_enable().

To include all the function into the tracer targets, this patch
creates a complete caller list just after sheep starts up.  This
achieves it with BFD (a part of binutils-dev) and makes the current
tracer code much simpler.

This can also remove trace.ld, and allows us to see a line number when
debugging with GDB.

Signed-off-by: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>
---
 collie/Makefile.am   |    2 +-
 configure.ac         |   14 ++--
 sheep/Makefile.am    |    2 +-
 sheep/trace/graph.c  |    6 +-
 sheep/trace/mcount.S |   28 -------
 sheep/trace/stabs.c  |  210 -----------------------------------------------
 sheep/trace/trace.c  |  222 +++++++++++++++++++++++++++++---------------------
 sheep/trace/trace.h  |   19 +----
 sheep/trace/trace.ld |   18 ----
 9 files changed, 143 insertions(+), 378 deletions(-)
 delete mode 100644 sheep/trace/stabs.c
 delete mode 100644 sheep/trace/trace.ld

diff --git a/collie/Makefile.am b/collie/Makefile.am
index 2b45b53..a336f11 100644
--- a/collie/Makefile.am
+++ b/collie/Makefile.am
@@ -29,7 +29,7 @@ collie_SOURCES		= farm/object_tree.c farm/sha1_file.c farm/snap.c \
 
 if BUILD_TRACE
 collie_SOURCES          += debug.c
-override CFLAGS         := $(subst -pg -gstabs,,$(CFLAGS))
+override CFLAGS         := $(subst -pg,,$(CFLAGS))
 endif
 
 collie_LDADD		= ../lib/libsheepdog.a -lpthread
diff --git a/configure.ac b/configure.ac
index ebaf241..50f822f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -289,6 +289,10 @@ if test "x${enable_trace}" = xyes; then
 	if [[[ $host != *x86_64* ]]]; then
 		AC_MSG_ERROR(tracer can be used on x86_64 architectures)
 	fi
+	AC_CHECK_LIB([bfd], [bfd_openr],,
+		AC_MSG_ERROR(requires binutils-dev))
+	AC_CHECK_HEADERS([bfd.h],,
+		AC_MSG_ERROR(requires binutils-dev))
 	AC_CHECK_LIB([rt], [clock_gettime],,
 		AC_MSG_ERROR(librt not found))
 	AC_DEFINE_UNQUOTED([HAVE_TRACE], 1, [have trace])
@@ -378,11 +382,9 @@ else
 fi
 
 if test "x${enable_trace}" = xyes && \
-		cc_supports_flag -pg && \
-		cc_supports_flag -gstabs ; then
-	AC_MSG_NOTICE([Enabling trace (-pg -gstabs)])
-	TRACE_CFLAGS="-pg -gstabs"
-	TRACE_LDFLAGS="-T$(pwd)/sheep/trace/trace.ld"
+		cc_supports_flag -pg ; then
+	AC_MSG_NOTICE([Enabling trace (-pg)])
+	TRACE_CFLAGS="-pg"
 	PACKAGE_FEATURES="$PACKAGE_FEATURES trace"
 else
 	TRACE_CFLAGS=""
@@ -393,7 +395,7 @@ CFLAGS="$ENV_CFLAGS $OPT_CFLAGS $GDB_FLAGS $OS_CFLAGS \
 	$TRACE_CFLAGS $COVERAGE_CFLAGS $EXTRA_WARNINGS $WERROR_CFLAGS \
 	-D_GNU_SOURCE -D_LGPL_SOURCE -std=gnu99"
 CPPFLAGS="$ENV_CPPFLAGS $ANSI_CPPFLAGS $OS_CPPFLAGS"
-LDFLAGS="$ENV_LDFLAGS $COVERAGE_LDFLAGS $OS_LDFLAGS $TRACE_LDFLAGS"
+LDFLAGS="$ENV_LDFLAGS $COVERAGE_LDFLAGS $OS_LDFLAGS"
 
 # substitute what we need:
 AC_SUBST([OS_DYFLAGS])
diff --git a/sheep/Makefile.am b/sheep/Makefile.am
index fe4a938..8b9cc10 100644
--- a/sheep/Makefile.am
+++ b/sheep/Makefile.am
@@ -41,7 +41,7 @@ sheep_SOURCES		+= cluster/zookeeper.c
 endif
 
 if BUILD_TRACE
-sheep_SOURCES		+= trace/trace.c trace/mcount.S trace/stabs.c trace/graph.c
+sheep_SOURCES		+= trace/trace.c trace/mcount.S trace/graph.c
 endif
 
 sheep_LDADD	  	= ../lib/libsheepdog.a -lpthread -lm\
diff --git a/sheep/trace/graph.c b/sheep/trace/graph.c
index ce2ff7a..deaf6a4 100644
--- a/sheep/trace/graph.c
+++ b/sheep/trace/graph.c
@@ -89,10 +89,8 @@ static notrace void graph_tracer(unsigned long ip, unsigned long *ret_addr)
 
 	memset(&trace, 0, sizeof(trace));
 
-	cr = trace_lookup_ip(ip, false);
-	assert(cr->namelen + 1 < TRACE_FNAME_LEN);
-	memcpy(trace.fname, cr->name, cr->namelen);
-	memset(trace.fname + cr->namelen, '\0', 1);
+	cr = trace_lookup_ip(ip);
+	pstrcpy(trace.fname, sizeof(trace.fname), cr->name);
 	get_thread_name(trace.tname);
 
 	*ret_addr = (unsigned long)trace_return_caller;
diff --git a/sheep/trace/mcount.S b/sheep/trace/mcount.S
index 69a9cbd..a621332 100644
--- a/sheep/trace/mcount.S
+++ b/sheep/trace/mcount.S
@@ -19,34 +19,6 @@
 #define ENTRY(x) \
         .text; _ALIGN_TEXT; .globl x; .type x, at function; x:
 
-ENTRY(mcount)
-	subq $0x38, %rsp
-	movq %rax, (%rsp)
-	movq %rcx, 8(%rsp)
-	movq %rdx, 16(%rsp)
-	movq %rsi, 24(%rsp)
-	movq %rdi, 32(%rsp)
-	movq %r8, 40(%rsp)
-	movq %r9, 48(%rsp)
-
-	movq 0x38(%rsp), %rdi
-	subq $INSN_SIZE, %rdi
-
-.globl mcount_call
-mcount_call:
-	call trace_stub
-
-	movq 48(%rsp), %r9
-	movq 40(%rsp), %r8
-	movq 32(%rsp), %rdi
-	movq 24(%rsp), %rsi
-	movq 16(%rsp), %rdx
-	movq 8(%rsp), %rcx
-	movq (%rsp), %rax
-	addq $0x38, %rsp
-
-	retq
-
 ENTRY(trace_caller)
 	subq $0x38, %rsp
 	movq %rax, (%rsp)
diff --git a/sheep/trace/stabs.c b/sheep/trace/stabs.c
deleted file mode 100644
index eeae153..0000000
--- a/sheep/trace/stabs.c
+++ /dev/null
@@ -1,210 +0,0 @@
-/*
- * Copyright (C) 2012 Taobao Inc.
- *
- * Liu Yuan <namei.unix at gmail.com>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License version
- * 2 as published by the Free Software Foundation.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <stab.h>
-
-#include "trace.h"
-
-/* referrence to the MIT JOS code */
-
-/* Entries in the STABS table are formatted as follows */
-struct stab {
-	uint32_t index;		/* index into string table of name */
-	uint8_t type;		/* type of symbol */
-	uint8_t misc;		/* misc info (usually empty) */
-	uint16_t desc;		/* description field */
-	uint32_t value;		/* value of symbol */
-};
-
-extern const struct stab __STAB_BEGIN__[];
-extern const struct stab __STAB_END__[];
-extern const char __STABSTR_BEGIN__[];
-extern const char __STABSTR_END__[];
-
-/*
-   stab_bsearch(stabs, region_left, region_right, type, addr)
-
-   Some stab types are arranged in increasing order by instruction
-   address.  For example, N_FUN stabs (stab entries with type ==
-   N_FUN), which mark functions, and N_SO stabs, which mark source files.
-
-   Given an instruction address, this function finds the single stab
-   entry of type 'type' that contains that address.
-
-   The search modifies *region_left and *region_right to bracket the
-   'addr'.  *region_left points to the matching stab that contains
-   'addr', and *region_right points just before the next stab.  If
-   *region_left > *region_right, then 'addr' is not contained in any
-   matching stab.
-
-   For example, given these N_SO stabs:
-   Index  Type   Address
-   0      SO     f0100000
-   13     SO     f0100040
-   117    SO     f0100176
-   118    SO     f0100178
-   555    SO     f0100652
-   556    SO     f0100654
-   657    SO     f0100849
-   this code:
-	left = 0, right = 657;
-	stab_bsearch(stabs, &left, &right, N_SO, 0xf0100184);
-   will exit setting left = 118, right = 554.
- */
-static notrace void stab_bsearch(const struct stab *stabs, int *region_left, int *region_right,
-		int type, uintptr_t addr)
-{
-	int l = *region_left, r = *region_right;
-	bool any_matches = false;
-
-	while (l <= r) {
-		int true_m = (l + r) / 2, m = true_m;
-
-		/* search for earliest stab with right type */
-		while (m >= l && stabs[m].type != type)
-			m--;
-		if (m < l) {	/* no match in [l, m] */
-			l = true_m + 1;
-			continue;
-		}
-
-		/* actual binary search */
-		any_matches = true;
-		if (stabs[m].value < addr) {
-			*region_left = m;
-			l = true_m + 1;
-		} else if (stabs[m].value > addr) {
-			*region_right = m - 1;
-			r = m - 1;
-		} else {
-			/* exact match for 'addr', but continue loop to find
-			 * *region_right
-			 */
-			*region_left = m;
-			l = m;
-			addr++;
-		}
-	}
-
-	if (!any_matches)
-		*region_right = *region_left - 1;
-	else {
-		/* find rightmost region containing 'addr' */
-		for (l = *region_right;
-				l > *region_left && stabs[l].type != type;
-				l--)
-			/* do nothing */;
-		*region_left = l;
-	}
-}
-
-/*
- * Fill in the 'info' structure with information about the specified
- * instruction address, 'addr'.
- *
- * Returns
- *  0 if information was found
- * -1 if not.
- *
- * NB: But even if it returns negative it has stored some
- * information into '*info'.
- */
-
-notrace int get_ipinfo(uintptr_t addr, struct ipinfo *info)
-{
-	const struct stab *stabs, *stab_end;
-	const char *stabstr, *stabstr_end;
-	int lfile, rfile, lfun, rfun, lline, rline;
-
-	info->file = "<unknown>";
-	info->line = 0;
-	info->fn_name = "<unknown>";
-	info->fn_namelen = 9;
-	info->fn_addr = addr;
-	info->fn_narg = 0;
-
-	stabs = __STAB_BEGIN__;
-	stab_end = __STAB_END__;
-	stabstr = __STABSTR_BEGIN__;
-	stabstr_end = __STABSTR_END__;
-
-	if (stabstr_end <= stabstr || stabstr_end[-1] != 0)
-		return -1;
-
-	/* Now we find the right stabs that define the function containing
-	 * 'eip'.  First, we find the basic source file containing 'eip'.
-	 * Then, we look in that source file for the function.  Then we look
-	 * for the line number.
-	 */
-
-	lfile = 0;
-	rfile = (stab_end - stabs) - 1;
-	stab_bsearch(stabs, &lfile, &rfile, N_SO, addr);
-	if (lfile == 0)
-		return -1;
-
-	lfun = lfile;
-	rfun = rfile;
-	stab_bsearch(stabs, &lfun, &rfun, N_FUN, addr);
-
-	if (lfun <= rfun) {
-		/* stabs[lfun] points to the function name
-		 * in the string table, but check bounds just in case.
-		 */
-		if (stabs[lfun].index < stabstr_end - stabstr)
-			info->fn_name = stabstr + stabs[lfun].index;
-		info->fn_addr = stabs[lfun].value;
-		addr -= info->fn_addr;
-		/* Search within the function definition for the line number. */
-		lline = lfun;
-		rline = rfun;
-	} else {
-		/* Couldn't find function stab!  Maybe we're in an assembly
-		 * file.  Search the whole file for the line number.
-		 */
-		info->fn_addr = addr;
-		lline = lfile;
-		rline = rfile;
-	}
-	/* Ignore stuff after the colon. */
-	info->fn_namelen = strchr(info->fn_name, ':') - info->fn_name;
-
-
-	/* Search within [lline, rline] for the line number stab. */
-	stab_bsearch(stabs, &lline, &rline, N_SLINE, addr);
-	if (lline <= rline)
-		info->line = stabs[lline].desc;
-	else
-		return -1;
-	/* Search backwards from the line number for the relevant filename
-	 * stab.
-	 * We can't just use the "lfile" stab because inlined functions
-	 * can interpolate code from a different file!
-	 * Such included source files use the N_SOL stab type.
-	 */
-	while (lline >= lfile &&
-		stabs[lline].type != N_SOL &&
-		(stabs[lline].type != N_SO || !stabs[lline].value))
-		lline--;
-	if (lline >= lfile && stabs[lline].index < stabstr_end - stabstr)
-		info->file = stabstr + stabs[lline].index;
-	/* Set fn_narg to the number of arguments taken by the function,
-	 * or 0 if there was no containing function.
-	 */
-	if (lfun < rfun)
-		for (lline = lfun + 1; lline < rfun && stabs[lline].type == N_PSYM;
-		     lline++)
-			info->fn_narg++;
-
-	return 0;
-}
diff --git a/sheep/trace/trace.c b/sheep/trace/trace.c
index e0a91c8..e4fcc0c 100644
--- a/sheep/trace/trace.c
+++ b/sheep/trace/trace.c
@@ -11,14 +11,12 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "trace.h"
+#include <bfd.h>
 
-#define TRACE_HASH_BITS       7
-#define TRACE_HASH_SIZE       (1 << TRACE_HASH_BITS)
+#include "trace.h"
 
-static struct hlist_head trace_hashtable[TRACE_HASH_SIZE];
-static LIST_HEAD(caller_list);
-static pthread_mutex_t trace_lock = PTHREAD_MUTEX_INITIALIZER;
+static struct caller *callers;
+static size_t nr_callers;
 
 static trace_func_t trace_func = trace_call;
 
@@ -33,9 +31,9 @@ union instruction {
 	} __attribute__((packed));
 };
 
-static inline int trace_hash(unsigned long ip)
+static notrace int caller_cmp(const struct caller *a, const struct caller *b)
 {
-	return hash_64(ip, TRACE_HASH_BITS);
+	return intcmp(a->mcount, b->mcount);
 }
 
 static notrace unsigned char *get_new_call(unsigned long ip, unsigned long addr)
@@ -56,13 +54,6 @@ static notrace void replace_call(unsigned long ip, unsigned long func)
 	memcpy((void *)ip, new, INSN_SIZE);
 }
 
-static inline void replace_mcount_call(unsigned long func)
-{
-	unsigned long ip = (unsigned long)mcount_call;
-
-	replace_call(ip, func);
-}
-
 static inline void replace_trace_call(unsigned long func)
 {
 	unsigned long ip = (unsigned long)trace_call;
@@ -77,66 +68,13 @@ static notrace int make_text_writable(unsigned long ip)
 	return mprotect((void *)start, getpagesize() + INSN_SIZE, PROT_READ | PROT_EXEC | PROT_WRITE);
 }
 
-notrace struct caller *trace_lookup_ip(unsigned long ip, bool create)
-{
-	int h = trace_hash(ip);
-	struct hlist_head *head = trace_hashtable + h;
-	struct hlist_node *node;
-	struct ipinfo info;
-	struct caller *new = NULL;
-
-	pthread_mutex_lock(&trace_lock);
-	if (hlist_empty(head))
-		goto not_found;
-
-	hlist_for_each_entry(new, node, head, hash) {
-		if (new->mcount == ip)
-			goto out;
-	}
-not_found:
-	if (get_ipinfo(ip, &info) < 0) {
-		sd_dprintf("ip: %lx not found", ip);
-		new = NULL;
-		goto out;
-	}
-	if (create) {
-		new = malloc(sizeof(*new));
-		if (!new) {
-			sd_eprintf("out of memory");
-			goto out;
-		}
-		new->mcount = ip;
-		new->namelen = info.fn_namelen;
-		new->name = info.fn_name;
-		hlist_add_head(&new->hash, head);
-		list_add(&new->list, &caller_list);
-		sd_dprintf("add %.*s", info.fn_namelen, info.fn_name);
-	} else {
-		sd_dprintf("%.*s\n not found", info.fn_namelen, info.fn_name);
-		new = NULL;
-	}
-out:
-	pthread_mutex_unlock(&trace_lock);
-	return new;
-}
-
-/*
- * Try to NOP all the mcount call sites that are supposed to be traced.
- * Later we can enable it by asking these sites to point to trace_caller,
- * where we can override trace_call() with our own trace function. We can
- * do this, because below function record the IP of 'call mcount' inside the
- * callers.
- *
- * IP points to the return address.
- */
-static notrace void do_trace_init(unsigned long ip)
+notrace struct caller *trace_lookup_ip(unsigned long ip)
 {
+	const struct caller key = {
+		.mcount = ip,
+	};
 
-	if (make_text_writable(ip) < 0)
-		return;
-
-	memcpy((void *)ip, NOP5, INSN_SIZE);
-	trace_lookup_ip(ip, true);
+	return xbsearch(&key, callers, nr_callers, caller_cmp);
 }
 
 notrace int register_trace_function(trace_func_t func)
@@ -151,26 +89,14 @@ notrace int register_trace_function(trace_func_t func)
 
 static notrace void patch_all_sites(unsigned long addr)
 {
-	struct caller *ca;
-	unsigned char *new;
-
-	pthread_mutex_lock(&trace_lock);
-	list_for_each_entry(ca, &caller_list, list) {
-		new = get_new_call(ca->mcount, addr);
-		memcpy((void *)ca->mcount, new, INSN_SIZE);
-	}
-	pthread_mutex_unlock(&trace_lock);
+	for (int i = 0; i < nr_callers; i++)
+		replace_call(callers[i].mcount, addr);
 }
 
 static notrace void nop_all_sites(void)
 {
-	struct caller *ca;
-
-	pthread_mutex_lock(&trace_lock);
-	list_for_each_entry(ca, &caller_list, list) {
-		memcpy((void *)ca->mcount, NOP5, INSN_SIZE);
-	}
-	pthread_mutex_unlock(&trace_lock);
+	for (int i = 0; i < nr_callers; i++)
+		memcpy((void *)callers[i].mcount, NOP5, INSN_SIZE);
 }
 
 notrace int trace_enable(void)
@@ -224,16 +150,126 @@ notrace void trace_buffer_push(int cpuid, struct trace_graph_item *item)
 	strbuf_add(&buffer[cpuid], item, sizeof(*item));
 }
 
+/* assume that mcount call exists in the first FIND_MCOUNT_RANGE bytes */
+#define FIND_MCOUNT_RANGE 32
+
+static unsigned long find_mcount_call(unsigned long entry_addr)
+{
+	unsigned long start = entry_addr;
+	unsigned long end = entry_addr + FIND_MCOUNT_RANGE;
+
+	while (start < end) {
+		union instruction *code;
+		unsigned long addr;
+
+		/* 0xe8 means a opcode of call */
+		code = memchr((void *)start, 0xe8, end - start);
+		addr = (unsigned long)code;
+
+		if (code == NULL)
+			break;
+
+		if ((int)((unsigned long)mcount - addr - INSN_SIZE) ==
+		    code->offset)
+			return addr;
+
+		start = addr + 1;
+	}
+
+	return 0;
+}
+
+static bfd *get_bfd(void)
+{
+	char fname[PATH_MAX] = {0};
+	bfd *abfd;
+
+	if (readlink("/proc/self/exe", fname, sizeof(fname)) < 0)
+		panic("failed to get a path of the program.");
+
+	abfd = bfd_openr(fname, NULL);
+	if (abfd == 0) {
+		sd_eprintf("cannot open %s", fname);
+		return NULL;
+	}
+
+	if (!bfd_check_format(abfd, bfd_object)) {
+		sd_eprintf("invalid format");
+		return NULL;
+	}
+
+	if (!(bfd_get_file_flags(abfd) & HAS_SYMS)) {
+		sd_eprintf("no symbols found");
+		return NULL;
+	}
+
+	return abfd;
+}
+
+/* Create a caller list which has a mcount call. */
+static int init_callers(void)
+{
+	int max_symtab_size;
+	asymbol **symtab;
+	int symcount;
+	bfd *abfd;
+
+	abfd = get_bfd();
+	if (abfd == NULL)
+		return -1;
+
+	max_symtab_size = bfd_get_symtab_upper_bound(abfd);
+	if (max_symtab_size < 0) {
+		sd_eprintf("failed to get symtab size");
+		return -1;
+	}
+
+	symtab = xmalloc(max_symtab_size);
+	symcount = bfd_canonicalize_symtab(abfd, symtab);
+
+	callers = xzalloc(sizeof(*callers) * symcount);
+	for (int i = 0; i < symcount; i++) {
+		asymbol *sym = symtab[i];
+		unsigned long ip, addr = bfd_asymbol_value(sym);
+		const char *name = bfd_asymbol_name(sym);
+
+		if (addr == 0 || !(sym->flags & BSF_FUNCTION))
+			/* sym is not a function */
+			continue;
+
+		ip = find_mcount_call(addr);
+		if (ip == 0) {
+			sd_dprintf("%s doesn't have mcount call", name);
+			continue;
+		}
+		if (make_text_writable(ip) < 0)
+			panic("failed to make mcount call writable");
+
+		callers[nr_callers].addr = addr;
+		callers[nr_callers].mcount = ip;
+		callers[nr_callers].name = strdup(name);
+		nr_callers++;
+	}
+	xqsort(callers, nr_callers, caller_cmp);
+
+	free(symtab);
+	bfd_close(abfd);
+
+	return 0;
+}
+
+/*
+ * Try to NOP all the mcount call sites that are supposed to be traced.  Later
+ * we can enable it by asking these sites to point to trace_caller.
+ */
 notrace int trace_init(void)
 {
 	int i;
 
-	if (make_text_writable((unsigned long)mcount_call) < 0) {
-		sd_dprintf("%m");
+	if (init_callers() < 0)
 		return -1;
-	}
 
-	replace_mcount_call((unsigned long)do_trace_init);
+	nop_all_sites();
 
 	nr_cpu = sysconf(_SC_NPROCESSORS_ONLN);
 	buffer = xzalloc(sizeof(*buffer) * nr_cpu);
diff --git a/sheep/trace/trace.h b/sheep/trace/trace.h
index 977b48f..f65aba8 100644
--- a/sheep/trace/trace.h
+++ b/sheep/trace/trace.h
@@ -7,20 +7,9 @@
 
 #include "sheep_priv.h"
 
-struct ipinfo {
-	const char *file;           /* Source code filename for EIP */
-	int line;                   /* Source code linenumber for EIP */
-	const char *fn_name;        /* Name of function containing EIP */
-	int fn_namelen;             /* Length of function name */
-	unsigned long fn_addr;      /* Address of start of function */
-	int fn_narg;                /* Number of function arguments */
-};
-
 struct caller {
-	struct list_head list;
-	struct hlist_node hash;
+	unsigned long addr;
 	unsigned long mcount;
-	int namelen;
 	const char *name;
 };
 
@@ -31,12 +20,8 @@ typedef void (*trace_func_graph_ent_t)(struct trace_graph_item *);
 
 /* graph.c */
 
-/* stabs.c */
-int get_ipinfo(unsigned long ip, struct ipinfo *info);
-
 /* mcount.S */
 void mcount(void);
-void mcount_call(void);
 void trace_caller(void);
 void trace_call(unsigned long, unsigned long *);
 extern const unsigned char NOP5[];
@@ -49,7 +34,7 @@ unsigned long trace_return_call(void);
   int register_trace_function(trace_func_t func);
   int trace_enable(void);
   int trace_disable(void);
-  struct caller *trace_lookup_ip(unsigned long ip, bool create);
+  struct caller *trace_lookup_ip(unsigned long ip);
   int trace_buffer_pop(void *buf, uint32_t len);
   void trace_buffer_push(int cpuid, struct trace_graph_item *item);
 
diff --git a/sheep/trace/trace.ld b/sheep/trace/trace.ld
deleted file mode 100644
index 031ada7..0000000
--- a/sheep/trace/trace.ld
+++ /dev/null
@@ -1,18 +0,0 @@
-SECTIONS
-{
-	stab : {
-		PROVIDE(__STAB_BEGIN__ = .);
-		*(.stab);
-		PROVIDE(__STAB_END__ = .);
-		BYTE(0) /* Force linker allocate memeory for this section */
-	}
-
-	stabstr : {
-		PROVIDE(__STABSTR_BEGIN__ = .);
-		*(.stabstr);
-		PROVIDE(__STABSTR_END__ = .);
-		BYTE(0)
-	}
-}
-
-INSERT AFTER .rodata
-- 
1.7.9.5




More information about the sheepdog mailing list